Aelian, On Animals 11. 1 (trans. Scholfield) (Greek natural history C2nd A.D.) :
"The race of the Hyperboreoi (Hyperboreans) and the honours there paid to Apollon are sung of by poets . . . This god has as [Hyperborean] priests the sons of Boreas (North Wind) and Khione (Chione) (Snow), three in number, brothers by birth, and six cubits in height."